EMG—aerodynamic measures for intervocalic /p/ production

Abstract

Simultaneous EMG and aerodynamic recordings were obtained to study the temporal relationships of lip and larynx activity during production of intervocalic /p/. Hooked-wire electrodes were used to sample activity in the following muscles: posterior cricoarytenoid, interarytenoid, quadratus labii inferior, and orbicularis oris inferior, Subglottic and intraoral pressures were sampled via tracheal and intraoral catheters, In the repeated utterances of an adult subject under normal talking conditions, it was found that although muscle activity in the posterior cricoarytenoid, quadratus labii inferior, and orbicularis oris inferior varied in onset and offset times relative to the production of /p/, the peak intraoral pressure developed for the stop was consistent from utterance to utterance: i.e., ±1 cm of water for all utterances. EMG and aerodynamic records were also made under two other conditions: the subject produced the same utterances with a fixed mandible, and then with a transoral pressure-release device. Despite limitations on jaw movement or the ability to impound oral air, the lip/larynx system was still able to achieve an intraoral pressure for /p/ that was consistent from utterance to utterance within each condition: i,e., ±1.25 cm of water for all utterances.